Signaling system



Aug. .6, 1940.

J. A. MILLER SIGNALING SYSTEM Original Filed June 25, 1937 W mE NO Hm IJOHN A. MILLER.

abtozmq event a line wire is broken PatemedA 6, 194m UNITED sTATEsPATENT! OFFICE 2,210,423 SIGNALING SYSTEM John A. Miller, Louisville,Ky., assignor" to Nacho'd & United States Signal 00., Incorporated,Louisville, Ky., a corporation of Kentucky Application June 25, 1937,Serial No.;150,222

Renewed December 13,1939

19 Claims. (Cl. 246-414) 'My'invention relates to a railway signaling 555-" tem adapted to govern car or train movements on a section of arailway having a plurality of entrances.

My invention has particular application to the signaling of a main linehaulage of a mine, which usually comprises asection' of a railway con-,

nected by turnouts leading to the various working sections of the mine.1 My invention embraces a-system of signaling, in which the signalcontrol apparatus for each entrance is entirely symmetrical. v

My invention embraces .a system'that requires but three line wires toconnect the apparatus at each entrance. r V

My invention also embraces a system of signaling in which only oneproceed signal is displayed under conditions of either nearly or exactlyshoes, and in which the control of. the signals governed by trolleycont'actors engaged by current collectors during their movement on thetrolley wire.

My invention still further resides in the arrangement of the signalcontrol circuits, such that the source of current for operating thecontrols governing the proceed? indication is obtained from only onesignal station.

It will be further obvious to those skilled in the art that, by reasonof the novel arrangement of. my signal system, there are many otherobjects that willbecome apparent as the specification is read inconnection with the accompanying drawing, in which: g

Figure 1 is a. diagrammatic representation of the circuits and apparatusillustrating one embodiment of my invention.

In Figure :lthe conductor or trolley wire tha supplies positivepotential to both the signaling system and the vehicles operating on therailway system is indicated by the character T, while, as is wellunderstood in the art, the, return COD-(111C?- due to falling slate,

tor sup-plying negative potential is either the earth, rails of arailway, or both, as conditions may require. j

Ashereinbefore expressed, one object of my invention-is to provide asignaling system,.for

a section of railway having a plurality of. entries into a main'section,in which each entry constitutes a signal station, wherein any desirednumber of stations may be connected to form a" unitarily controlledsignal system. Since three stations may be conveniently. employed toillus trate-the operation of such a signaling system, Fig. 1diagrammatically illustrates such an embodiment. I In Fig. 1, thesection of a railway extending between stations I and 3 may be regardedas the main section, while the section of a railway connecting station 2maybe considered a turnout connecting a working Isection of the mine.

Although the accompanying drawing illustrates one embodiment of myinvention employing a particular form of mechanically actuated trolleycontactor, it is to be understood that any other suitable form ofcontactor,. track instrument, or track circuit, may be substitutedtherefor without departing from the spirit of my in-' vention.

In the embodiment of. my invention; each signal station is providedwith'two vehicle-controlled contact mechanisms, which are adapted to beengaged by the current collector of a moving car to close itscorresponding signal control circuit. These vehicle-controlled contactmechanisms may comprise suitable mechanically movable contact members,indicated at station'l as Sl and NI respectively, that are defiectableinopposite directions by the current collector according to the directionof movement of thecar.

' At station I, the movable contact member SI is provided withastationary contact 1, which, as indicated by the. adjacent arrow, isengaged by the contact member Si only whenthe car enters the signaledsection. Itwill be further noted that the movable contact member Ni isprovided with a stationary contact 10,'which, as indicated by'theadjacent arrow, is engaged by the contact member NI only when thecar'leaves the signaled v section.

The signal indications at each station are diagrammatically illustratedas signal lamps, how-.- ever, it is understood that any suitableformofsignaling, means, may be substituted for such signal lamps. u

The signal lamps are adapted to convey to the O erator of. a..vehiclethe condition. of. the signaled territory, that is, whether sameis occupied by moving trains, and the direction in which such trains aremoving. It is to be understood that these signal lamps are provided withsuitable coloring roundels to distinguish the indications. vention, Iemploy red roundels for lamps Ri, R2 andl Rt to denote Stop, andgreenroundels for lampsGi; G2 and to indicate Proceed. A similarredroundel is provided for signal lamp R.

In Fig. 1 similar relays are employed at each signal station At stationi these relays are, namely; a quicleacting neutral relay Mi, a slowrelease quick pickup neutral relay Li and a mechanical interlockingrelay Ai--Ci. he mechanical interlocking relay be of any suitable typein which, for instance, contact arm Di remains in one position after theoperating. coil of. relay Ai has beenenergised, and remains in anotherposition after the operating coil of relay Ci has been energized. Itisto be noted that the similar relays at each station, together with theother similar apparatuses, are designated by similar characters. relayatstation 3, corresponding to' the neutral relay designated at station ias Mi, is designated as M3.

In the embodiment of my invention, the mechanical interlocking relay isof the type in which the armature Di is retained in its operatedposition by a mechanical latch Xi, and restored to its normal positionby the operation of an armature Bi to release the mechanical latch Xi. n

Before proceeding with a-detailed description of the operation of myinvention, notation will be made of the normal condition of the relaysand signals. Normally, with no trains occupying the signaled section,all signals are held at dark, and neutral relays Mi, M2 and M3 areretained de-energized, while the neutral relays Li, L2 and L3 areretained energized. Similarly the operating coils of relays Ci, C2 andC3 are de-energlzed at all times excepting when one of the 're-" storingtrolley contactors Ni, N2 or N3 is being operated by a currentcollectorof a car leaving the signaled section. Also the operating coilsoi relaysAl, A2 and A3 are de-energized at all times excepting when itscorresponding trolley contactor Si, S2 or S3 is operated by the currentcollector of a car entering the signaled section.

Observing the circuits of station i, it Will'be noted that the operatingcoil of relay L! is normally energized retaining its armature J i inengagement with its front contact 4, thereby normally connecting theoperating coil of relay A! to the earth or negative return. Thus, aslong as the operating coils of the L relays are retained energized, thesignals are held dark, and the operating coils of the A relays are heldin condition to be energized in response to an operation of itscorresponding trolley contactor. However, when the operating coils ofthe L relays are de-energized, the operating coils of the A relays arewithheld from energization, and

' a circuit is completed at each signal station to one or other of therespective signal lamps, dependent upon the selection determined by therespective M relay. From the foregoing it will be apparent that,regardless of the manner in which the operating coils of the L relaysare deenergized, whether due to open circuited coils, short. circuitedcoils, faulty ground connections,

In the illustrated embodiment of my in- For instance, the neutral of toline wire 52.

the A relays'of each station.

broken line wire, etc., the operating coils of the A relays will belocked out, that is, withheld from operation, and a local circuit to thesignal lamps at each station completed.

In Fig. 1 it is important to observe that the operating coils of relaysLi, L2, L3 each have one terminal directly connected to the negativereturn and the other terminal connected to a common line wire extendingbetween the three signal stations, which line wire includes wires 26 and29. Thus, at station 3, wire connects one terminal of the operating coilof relay L3 to the negative return, while wire iiiia connects the otherterminal thereof to line wire 26. Similarly, at station i, wire 28connects one terminal of the operating coil of relay Li to the negativereturn,

' while wire El connects the other terminal thereof to line wire 2%.Likewise, at station 2, wire 3i! connects one terminal of the operatingcoil of relay L2 to the negative return, while the other terminal of thecoil of relay L2 is connected to line wire 29. Obviously, line wire 29is an extension of line wire 26, therefore these permanently connectedwires will hereinafter be referred to as the first line wire 25-29.Accordingly, whenever thefirst line wire 2529 is at positive potential,the operating coils of relays Li, L2 and L3 are energized.

Similarly, each of the operating coils of relays Ci, C2 and C3 have oneterminal directly connected to the negative return and the otherterminal. connected to a restoring line wire extending between the threestations, which restoring line wire includes wires 63 and 66. Thus, atstation 3, wire iii connects one terminal of the operating coil of relayCi to the negative return while wire ii connects the other terminalthere- Similarly, at station I, wire $5 connects one terminal or" theoperating coil of relay Ci to the negativereturn, while Wire 64 connectsthe other terminal thereof to line wire 63. Likewise, at station 2, wire67 connects one terminal of the operating coil of relay C2 to thenegative return, while the other terminal thereof is connected to linewire 66. Obviously, line wire M5 is an extension of line wire 63,therefore these permanently connected Wires will hereinafter be referredto as the restoring line wire 63 8E; Accordingly, whenever the restoringline wire 63-86 is at positive potential, theoperating coils of relaysCi, C2 and C3 are energized.

To provide for the placing of the restoring line wire tit-iii; atpositive potential, a normally open contact of each restoring trolleycontactor is connected thereto. Thus, at station 3, contact H isconnected to the restoring line Wire 636G. Similarly, at station i, thecontact ii) is connected to the restoring line wire 63-456, and, atstation 3, contact 6t is connected to the restoring line Vile 63%.

As hereinbefore described, each of the aforesaid contacts Sil, it and iiare electrically connected to the positive conductor T, when the movableelement of the corresponding restoring contactor is engaged by a trolleywheel leaving the signaled section.

To provide for the placing of the first line wire Eat-29 at positivepotential, a series line circuit is provided between stations i, 2 and3, which line circuit includes'a normally closed switch on In theillustrated embodiment, this series line circuit begins at station iwith wire 5, which wire connects the armature Di of relay Ai to thepositive conductor T. From the normally engaged back contact IQ ofarmature DI, the line circuit continues via wire 20, which wire connectsthe contact I9 to armature D2 of relay A2 at station 2. From station 2,the line circuit continues via wire 22, which wire connects the normallyengaged back contact 2| of armature D2 to the armature D3 at station 3.

corresponding A relay and a jumper wire, to the first line wire. Thus,at station 3, which is the last station in the illustration, thenormally engaged back contact 23 of armature D3 is connected by thejumper wire 24 to the first line wire 26-29. Obviously, as long as eachof the normally closed switches DI-I 9, D22I and D3-23 remain closed,the first line wire 26-29 is retained at positive potential, and each ofthe operating coils of relays LI, L2 and L3 are energized. Thus, theinvention embraces a system in which the operating coils of therestoring relays are permanently connected in multiple, and temporarilyelectrically connected to a source of current via a circuit including anormally open contact, which contact is temporarily closed as the trainleaves the signaled section.

The invention further embraces a system in which the operating coils ofthe signal controlling relays are likewise permanently connected inmultiple and normally electrically connected to a source of current viaa series line circuit including a normally closed switch at eachstation, which retains the signal controlling relays normally energized.Having thus enumerated the essential features of my invention, I willnoW describe their operation, and the manner in which they arestructurally embodied in a signaling system.

Vehicle operation With no car or train in the signaled section, allsignals are held in a normally dark condition. The control efiectingthis condition of the signals, includes the series line circuit, whichretains the operating coils of the L relays energized. In Fig. 1, thisseries line circuit is completed from the positive conductor T atstation I, through wire 6, armature DI, contact I9, wire 20, armatureD2, contact 2I, wire 22, armature D3, contact 23, jumper wire\ 24, wire24a, operating coil of relay L3, wire 25 to the negative return. It willalso be observed that the operating coil of relay LI is likewiseconnected to positive potential from jumper wire 24, through wires 26and 21; the operating coil of relay LI being connected to the negativereturn through wire 28.

The operating coil of relay L2 is likewise connected to positivepotential from the jumper wire 24 I through wires 26 and 29; theoperating coil of re-- lay L2 being connected to the negative returnthrough wire 30. The latter mentioned circuits from jumper wire 24, toeach of the operating coils of the L relays, merely connects each of theoperating coils in a multiple circuit; the jumper wire 24 serving tosupply positive potential obtained from station I through a series linecircuit that includes an armature and back contact of the A relays ateach signal station.

With further reference to Fig. 1 it will be noted that the N restoringcontactors are each electrically connected to the restoring line Wireilk-66, and that the operating coils of the C relaysat each signalstation are connected to the restoring line wire forenergization-whenever one At the last station the series line circuit isv connected, via the normally closed switch of the of the restoringcontactors is operated bya car leaving the signaled section.

Assuming that a vehicle enters at station I, the engagement of itscurrent collector with its restoring contactor NI will have no effect onthe operation of the system. However, when the trolley wheel of theentering vehicle engages the setting contactor SI, a circuit iscompleted from the trolley conductor T through contact I, wire 2,operating coil of relay AI, wire 3, contact 4, armature J I, wire to thenegative return. This energization of the operating coil of relay AIwill cause the armature DI to disengage its back contact-I9, and engageits front contact I. This disengagement of back contact I9 opens theseries line circuit including wires 6, 20, 22 and 24, which normallyretains the first line wire 26-29 at positive potential, therebyvde-energizing the operating coils of the L relays at each respectivesignal station. The de-energization of the operating coils of the Lrelays will cause their respective armatures to release from theiroperated positions. When thearmature J I of relay LI is released, thecircuit of the operating coil of relay AI is opened by the disengagementof contact 4, and the GI signal lamp circuit is connected to thenegative return through back contact II armature J I and wire 5.

When the armature DI of relay AI was operated the mechanical latch XImoved into the path of the armature and mechanically retained same inits operated position. In its operated position the armature DI engagedfront contact I and completed a circuit for energizing the operatingcoil of relay. MI, the latter circuit being completed from the positiveconductor T, through wire 6, armature. DI, contact 1, wire 8, operatingcoil of relay MI, wire 9 to the negative return. This energization ofthe operating coil of relay MI will, cause armature HI. to disengageback contact I3 and to engage front contact I5. Therefore, the circuitof the proceed signal lamp GI is completed from the positive conductorT, through wire I8,signal lamp GI, wire I6, contact l5, armature HI,wire I2, contact I.I, armature J I wire 5 to the negative return. Theopening of the series line circuit through the operation of armature DI,also de-energized the operating coil L2 at station 2, thereby causingits armature J2 to disengage its front contact and to engage its backcontact Ila. Inasmuch as the operating coil of relay M2 at station 2 isnot energized, the circuit of the stop signal R2is completed from thepositive conductor T, through wire Ila, signal lamp R2, wire'I4a,contact I3a, armature H2, wire I2a, contact Ila, armature J2, wire 5a tothe negative return. Similarly the releasing of armature'J 3 at station3 completed the circuit of the stop signal R3 fromthe positive conductorT, through wire IIb, signal lamp R3, wire I4b', contact I3b, armatureH3, Wire I2b, contact IIb, armature J3, wire 5b to the negative return.It is important to note that the release of armatures J2 and J3 atstations 2 and 3, respectively, disconnected the operating coils ofrelays A2 and A3 from the negative return, thereby preventing theenergization of these operating coils should a car attempt to enter thesignaled section at stations 2 and 3 with the stop signals R2 and R3displaying.

The car entering at station I, and occupying the signaled section, mayleave at any one of the stations and restore the system to normal. Itwill be assumed that the car leaves the signaled section at station 3.Therefore, when the cur- 15 rent collector of the car engages thecontactor S3, no change in the controls will be efiected. However, whenthe current collector engages the contactor N3, the contact ii isconnected. to trolly or positive conductor T, thereby placing positivepotential on the restoring line wire including wires 83 and (56. Aspreviously mentioned, each of the operating coils of the relays Ci, C2and C3 are permanently connected to the restoring line wire. Therefore,placing the restoring line wire at-positive potential will cause theoperating coils of the relays Ci, C2 and C3 to be momentarily energized.The operation of armatures B2 and B3 of relays C2 and C3 operates theirrespective mechanical latches X2 and X3, but since armatures D2 and D3were not previously operated, no further operation of these relays ismade. At sta tion i, however, the operation of the armature Di operatesthe mechanical latch Xi and moves same out of the path of armature Di,thereby permitting armature Di to restore to its normal position.

The resultant restoration of armatures J i, J2 and J 3 to their normalpositions restores the signal lamps at each station to their normal darkconditions, and connects the operating coil of each respective A relayto the negative return so that it may be operated by a car entering thesignaled section.

In the preceding description it was assumed that a single car entered atstation i. To explain the operation of my invention under simultaneousentrance, it will be assumed that a car enters at station 2 simultaneouswith the car at station i Under this condition of operation, theoperating coils of relays Al and A2 are simultaneously energized. Thesimultaneous operation of armatures Di and D2 opens the series linecircuit at both stations i and 2, and thereby deenergizes the operatingcoils of relays Li L2 and L3. Inasmuch as armatures Di and D2 weresimultaneously operated, the mechanical latches Xi and X2 retain theirrespective armatures in their operated positions.

Referring particularly to the circuits of station I, it will be notedthat the operation of armature Di removed positive potential fromarmature D2 of station 2, and completed the circuit for the energizationof the operating coil of relay Mi, thereby permitting energization ofthe proceed signal Gi in the same manner as described in connection witha single car entering at station i. Similarly, the stop signal R3 atstation 3 is displayed. Thus with cars entering simultaneously atstations i and 2, only the car approaching at station i receives theproceed signal.

I will now assume that the car at station 2 operated the settingcontactor S2 slightly before the car at station i operated its settingcontactor Si. Under this condition of operation it will be apparent thatthe operating coil of relay A2 is energized before the operating coil ofrelay Al. It will also be apparent that, if this time is suflicient topermit the armature J i of relay Ll to disengage its front contact tbefore the operating coil of relay Ai can operate its armature Di, themechanical latch X2 will retain armature D2 operated while armature Diwill remain in its unoperated position. Thus, the armature D2 beingconnected to positive potential T via wire 28, contact i9, armature Diand wire 8, will bring about the energization of the operating coil ofrelay M2, therefore, the armature H2 will disengage its back contact i3aand engage its front contact l5a thereby permitting energization of theproceed signal G2. At station i, however, since the armature Di was notoperated, the operating coil of relay Mi will not be energized.Therefore, the release of armature J i completes the circuit of the stopsignal Hi from the positive conductor T through wire it, signal lamp RI,wire it, contact i3, armature Hi, wire i2, contact ii, armature J i,wire 5 to the negative return. Inasmuch as no car operated at station 3,the stop signal R3 is displayed as hereinbefore mentioned.

From the foregoing it will be apparent that in order for the proceedsignal to be displayed at a station remote from the location Where thesignal control wire is connected to positive potential, it is necessaryfor the armature of the respective A relay to be operated before thearmature of the A relay nearer the said location. Thus, according toFig. 1, under simultaneous operation of armatures Di D2 and D3, stationi receives the proceed signal. 7 With simultaneous operation ofarmatures D2 and D3 station 2 receives the proceed signal. However,under any circumstances if, for instance, armature D3 is operated beforearmature Di or D2, the operating coil of relay 3 is energized, whichpermits the proceed signal G3 to be displayed at station 3. Thus, thesignal control circuits are arranged to permitbut one proceed signal tobe displayed at one time.

As described under the operation of a single car receiving a proceedsignal at station l, under simultaneous operation the car receiving theproceed signal may leave the signaled section at any station, andoperate to restore the signals to normal as previously described.Therefore, regardless of whether the restoring contactor Ni, N2 or N3 isoperated, the relays and signals are restored to normal in the samemanner.

At station 2 a stop signal R. is provided andlocated to stop a carapproaching station 2 before operating the setting or restoringcontactors S2 and N2, whenever the signaled section is occupied.

Referring to the circuits of station 2, it will be noted that wheneverthe armature J 2 of relay L2 is released, the circuit of the stop signalis completed from positive potential T, through wire 36, signal lamp R,wire 35, Wire iia, contact Ha, armature J 2, wire 5a to the negativereturn. The purpose of stop signal R is to prevent cars approachingthesignaled section from passing its respective setting contactor whilethe signaled section is occupied, and it is to beunderstood that asimilar stop signal is to be provided at stations i and 3 when thisfeature is required.

Referring further to Fig. 1 it will be noted that each of the relays Li,L2 and L3 is provided with a convenient means for slightly retarding therelease of their respective armature. The purpose of this arrangement isto assure operating current flowing through the operating coil of thecorresponding A relay sufficiently long to permit its respectivearmature to be mechanically latched in its operated position. Forinstance, at station i when the operating coil of relay Al is energizedthe armature Di is operated and instantly de-energizes the operatingcoil of relay Li. The armature J i of relay Li will not immediatelyrelease, thereby permitting the operating coil of relay Al to beenergized sufficiently long to assure armature Di engaging its frontcontact '5.

Having thus described my invention, I claim:

1. In a control system comprising similar apparatusat each of aplurality of separate statil tions, the apparatus at each stationcomprising a normally open electric circuit including an electro-magnet,a vehicle-responsive switch for closing the said circuit upon the entryof a car into the block; an armature operatedby the said electro-magnct;a second electro-magnet normally energized; an armature normallymaintained in its operated. position by the said second electromagnet;means, controlled by the armature of the second mentionedelectro-magnet, to render ineffective the said electric circuit when thesaid second electro-magnet is de-energized; means, controlled by thearmature of the first electromagnet, to de-energize the said secondelectromagnet to render the said electric circuit ineffective; signalingmeans; and means, controlled by the armature of the second mentionedelectromagnet, operating said signaling means when the said secondelectro-magnet is de-energized.

2. In a control system comprising similar apparatus at each of aplurality of separate stations, the apparatus at each station comprisinga normally open electric circuit including an electromagnet; avehicle-responsive switch for closing the said circuit upon the entry ofa car into the block; an armature operated by the said electromagnet; asecond electro-magnet normally energized; an armature normallymaintained in its operated position by the second electro-magnet; athird electro-magnet; means controlled by the said third electro-magnetand operable to retainthe first mentioned armature in its operatedposition; means, controlled by the operation of the first mentionedarmature, to de-energize the said second electro-magnet; signalingmeans; means, controlled by the armature of the second mentionedelectro-magnet, operating said signaling means when the said secondelectro-mag'net is deenergized; and means, responsive to a car leavingthe block, to energize the said third electromagnet, to renderineffective the said retaining means, thereby restoring the saidarmature to its unoperated position when the said retaining means isrendered ineffective, so as to re-energize the said secondelectro-magnet.

3. In a railway block signaling system comprising similar apparatusateach of a plurality of separate stations, the apparatus at each stationcomprising a normally open electric circuit including an electro-magnet;an armature for the said electro-magnet; means, actuated upon the entryof a car into the block, for closing the said circuit; asecondelectro-magnet normally energized; an armature normally maintained inits operated position by the said second electro-magnet; a thirdelectro-magnet; a mechanical latch controlled by the said thirdelectro-magnet, and adapted to retain the armature of the firstmentioned electro-magnet in its operated position; a fourthelectro-magnet and an armature operated thereby; stop and proceedsignals controlled by the last mentioned armature; means, controlled bythe operation of the armature of the first mentioned electro-magnet, tode-energize the said second electro-magnet; means, controlled by thesaid'operation of the said first mentioned armature, to energize thesaid fourth mentioned electro-magnet; means, controlled by therelease ofthe armature'of the said second electro-magnet from its operatedposition, to render the circuit of the first mentioned electro-ma'gnetineffective to a car entering the block; and means, controlled by therelease of the said armature of the said second electro-magnet, tooperate the said proceed signal, when the armature of the said fourthmentioned l'electro-magnet is operated; and means, controlled by thesaid operation of the armature of the said first mentionedelectro-magnet, to. de-

energize the corresponding second electro-magnets at each of the otherstations, to operate the said stop signals at each of the said otherstations.

4. In a railway block signaling system, as set forth in claim 3,comprising means, controlled by a vehicle leaving the block, to energizethe said third electromagnet to remove the mechanical latch from thearmature of the first men-. tioned electro-magnet, and to therebyre-energize the said second electro-magnets at each station todiscontinue the operation of the said signals. 9 i

5. In a railway block signaling system comprising a normally openelectric circuit including an electro-magnet; means, actuated upon theentry of a car into the block, for closing the said circuit; an armatureoperated by the said electromagnet; a second electro-magnet; means,controlled by the said second electro-magnet, to retain the saidarmature in its operated position; a third electro-magnet normallyenergized; means, controlled by'the said armature, to deenergize thesaid third electro-magnet; a fourth electro-magnet normallyde-energized; means, controlled by the said armature, to energize thesaid" fourth electro-magnet; a proceed signal; and means, controlled bythe said de-energization of'the said third electro-m'agnet and the saidenergiz'ation of the fourth" electro-magnet, to operate the said proceedsignal.

' 6. In a railway block signaling system, as set forth in claim 5,comprising means, responsive to a vehicle leaving-the said block, toenergize the said second electro-magnet to render ineffective the saidretaining means, and to thereby restore the "said'third and 'fourthelectro-magnets to their normal conditions. I

'7. In a control system for railway block signaling comprising anormally open circuit incuit includingan. electro-magnet; means,actuated upon the entry of a car into the block, for closing the saidcircuit; an armature operated by the-said electro-magnet; means operableto retain the said armature in its operated position; a" secondelectro-magnet normally energized; a'switchin the'said circuit normallymaintained closed by the said second electro-magnet; means, controlledby the operation of the said armature, to dc-energize the said secondelectromagnet to open the said switch; a proceed sigthe first mentionedelect'ro-magnet, when the said armature is in its operated position, tooperate the said proceed signal;

8. In a control system for railway block signaling, as set forth inclaim '7, comprising means, responsive to a vehicle leaving the saidblock, to discontinue the operation of the said'retaining means, and tothereby restore the said armature to its normal position.

9. A railway block signaling system for a plurality of separatedstations having, in combination, a source of power; a first lineconnection extending to' each station; a signal controlling relay ateach station; a normally energized operating coil for each signalcontrolling relay, each of the latter'operating coils having oneterminalconnected tothe first line connectioniand the other terminal connectedto one terminal of other terminal of the source of power, the saidsecond line connection including the normally closed switch at eachstation connected in series therewith; control means at each stationoperable to open the corresponding normally closed switch, to disconnectthe first line connection from the other terminal of the source ofpower, and thereby to de-energize each of the operating coils of thesaid signal controlling relays; means at each station operable to retainthe corresponding control means operated; a second relay at eachstation; a normally de-energized operating coil'for each-second relay,each of the latter operating coils having one terminal connected to thesaid one terminal (Y of the source of power; means at each station,actuated by the operation of its corresponding control means, forconnecting the other terminal of the operating coil of the correspondingsecond relay to the said other terminal of the source of power; anormally dark proceed signal at each station; means, controlled by thede-energization of the operating coil of a signal controlling relay andthe energization of the operating coil of the corresponding'seoondrelay, for operating the corresponding proceed signal; a normally darkstop signal at each station; means controlled by the de-energization ofthe operating coil of a signal controlling relay and the de-energizationof the operating coil of the corresponding second relay, for operatingthe corresponding stop signal; and means, responsive to a car leavingthe signal block, for rendering ineffective the said retaining means,thereby to restore the relays and signals to normal conditions.

10. A railway block signaling system for a plurality of separatedstations having, in combination, a source of power; a first lineconnection extending to each station; a signal controlling relay at eachstation; a normally energized operating coil for each signal controllingrelay, each of the latter operating coils having one terminal connectedto the first line connection and the other terminal connected to oneterminal of the source of power; a normally closed switch at eachstation; a second line connection connecting the said first lineconnection to the other terminal of the source of power, the said secondline connection including the normally closed switch at each stationconnected in series therewith; control 'means at each station operableto open the corresponding normally closed switch, to disconnect thefirst line connection from the other terminal of the source of power,and thereby to de-energize each of the operating coils of the saidsignal controlling relays; means at each station operable to retain thecorresponding control'means operated; signalling means at each station;means, controlled by the de-energization of the said operating coils,for operating the corresponding signaling means; and means responsive toa car leaving the said block, for rendering ineffective the saidretaining means, thereby to restore the said operating coils to theirnormally energized condition.

11. A railway 'block signaling system for a plurality of separatedstations having, in combination, a source of power; a first lineconnection extending to each station; a signal controlling relay at eachstation; a normally energized operating coil for each signal controllingrelay, each of the latter operating coils having one terminal connectedto the first line connection and the other terminal connected to oneterminal of the source of power; a normally close'dswitch at eachstation; a second line connection comiecting the said first lineconnection to the other terminal of the source of power, the said secondline connection including the normally closed switch at each stationconnected in series therewith; control means at each station operable toopen the corresponding normally closed switch, to disconnect the firstline connection from the other terminal of the source of power, and tothereby de-energize each of the operating coils of the said signalcontrolling relays; means at each station operable to retain thecorresponding control means operated; a second relay at each station; anormally de-energized operating coil for each second relay, each of thelatter operating coils having one terminal connected to the said oneterminal of the source of power; means at each station, actuated by theoperation of its corresponding control means, for connecting the otherterminal of the operatingcoil of the corresponding second relay to thesaid otherterminal of the source of power; means controlled by theopening of one or more of the said switches, providing energization ofonly one of the operating coils of the said second relays; anormallydark proceed signal at each station; means, controlled by thede-energization of the operating coil of a signal controlling relay andthe energization of the operating coil of the corresponding secondrelay, for operating the corresponding proceed signal; a normally darkstop signal at each station; means controlled by the de-energization ofthe operating coil of a signal controlling relay and the de-energizationof the operating coil of the corresponding second relay, for operatingthe corresponding stop signal; and means, responsive to a car leavingthe signal block, for rendering ineffective the said retaining means,thereby to restore the relays and signalsto normal conditions.

12. A railway block signaling system for a plurality of separatedstations, having, in combination, a source of power; a signalcontrolling relay at each station; a normally energized operating coilfor eachsignal controlling relay; a normally closed line circuitincluding the operating coil of each signal controlling relay and thesource of power 'for retaining the operating coil of each signalcontrolling relay normally energized; a normally closed switch at eachstation, each switch included in the said circuit and operable to openthe said circuit for de-energizing all of the said operating coils;control means at each station for operating'the corresponding switch toopen the said circuit; means at each station operable to retain thecorresponding control means operated; a second relay at each station; anormally de-energized operating coil for each second relay; a normallyopen control switch at each station closed by the operation of thecorresponding control means; means at each station controlling theclosing of each respective normally open switch, for energizing theoperating coil of the corresponding second relay; a normally darkproceed signal at each station; means, controlled by the de-energizationof the operating coil of a signal controlling relay, and theenergization of the operating coil of the corresponding second relay,for operating the corresponding proceed signal; a normally dark stopsignal at each station; means, controlled by the de-energization of theoperating coil of a signal controlling relay and the de-energization oftheoperating coil of the corresponding second relay, for operating thecorresponding stop signal; and

means, responsive to a car leaving the signal block, for renderinginefiective the said retaining means, thereby to restore the relays andsignals to normal conditions.

13. A railway block signaling system for a plurality of separatedstations having, in combi nation, a source of power; a signalcontrolling relay at each station; a normally energized operating coilfor each signal controlling relay; a normally closed line circuitincluding the operating coil of each signal controlling relay and thesource of power for retaining the operating coil of each signalcontrolling relay normally energized; va normally closed switch at eachstation, each switch included in the said circuit and operable to openthe said circuit for de-energizing all of the said operating coils;signaling means at each station; andmeans at each station, responsive tothe de-energization of the operating coil of the corresponding signalcontrolling relay, for operating the corresponding signaling means.

14. A railway block signaling system for a plurality of separatedsignalstations having, in combination, a source of power; a signalcontrolling relay at each station; a normally energized operating coilfor each signal controlling relay; a normally closed line circuitincluding the operating coil of each signal controlling relay and thesource of power for retaining the operating coil of each signalcontrolling relay normally energized; a normally closed switch at eachstation, each switch included in the said circuit and operable to openthe said circuit for de-energizing all of the said operating coils; anormally de-energized operating coil at each station, which, whenenergized, operates the corresponding normally closed switch; a secondswitch at each station normally retained closed by the normallyenergized operating coil of the corresponding signal controlling relay;a normally open electric circuit at each station including thecorresponding normally closed second switch connected in seriestherewith; means at each station, actuated upon the entry of a car intothe signal block at the corresponding station for closing thecorresponding normally open circuit;

means at each station operating to retain the corresponding firstmentioned normally closed switch operated, when the correspondingnormally de-energized operating coil is energized; signaling means ateach station; means at each station, responsive to the de-energizationof the operating coil of the corresponding signal controlling relay, foroperating the corresponding signaling means; and means, responsive to acar leaving the said signal block, for rendering ineifective the saidretaining means.

15. A railway block signaling system for a plurality of separatedstations having, in combination, a source of power; a normally-energizedrelay at each station, each relay having a normallyenergized relay coil;a normally-closed line-circuit including the relay coil at each stationand the source of power for retaining the relay coil at each stationnormally energized; a normallyclosed switch at each station included inthe said circuit, each switch operable to open the said circuit forde-energizing all of the said relay coils; control means at each stationfor operating the corresponding switch to open the said circuit;

signaling means at each station; and means at each station, operated bythe de-energization of the corresponding relay coil, for operating thecorresponding signaling means.

16. A railway block signaling system for a pluone terminal of the sourceof power; a normally closed switch at each station; a second lineconnection connecting the said first line connection to the otherterminal of the source of power, the said second line connectionincluding the normally closedswitch at each station connected in seriestherewith; control means at each station operable to open thecorresponding normally closed switch, for disconnecting the first lineconnection from the said other terminal of the source of power, andthereby to ole-energize the electromagnet at each station; signalingmeans at each station; and means at each station, operating in responseto the de-energization of the corresponding electro-magnet, fordisplaying the corresponding signaling means.

17. A railway block signaling system for a plurality of separatedstations having, in combination, a source of power; a first lineconnection extending to each station; a normally-energizedelectro-magnet at each station, each magnet having one terminalconnected to the first line connection and its other terminal connectedto one terminal of the source of power; a normally closed switch at eachstation; a second line connection connecting the said first lineconnection to the other terminal of the source of power, the said secondline connection including the normally closedswitch at each stationconnected in series therewith; control means at each station operable toopen the corresponding normally closed switch, for disconnecting thefirst line connection from the said other terminal of the source ofpower, and thereby to de-energize the electromagnet at each station; anormally-open switch at each station, closed by the operation of thecorresponding control means; a proceed signal at each station; means ateach station controlled by the closing of the corresponding normallyopenswitch, for displaying the corresponding proceed signal; a stop signalat each station; and means at each station, controlled by thede-energization of the corresponding electro-magnet, for displaying thecorresponding stop signal.

18. A railway block signaling system for a plurality of separatedstations having, in combination, a source of power; a first lineconnection extending to each station; a normally-energizedelectro-magnet at each station, each magnet having one terminalconnected to the first line connection and its other terminal connectedto one terminal of the source of power; a normally closed switch at eachstation; a second line connection connecting the said first lineconnection to the other terminal of the source of power, the said secondline connection including the normally closed switch at each stationconnected in series therewith; control means at each station operable toopen the corresponding normally closed switch, for disconnecting thefirst line connection from the said'other terminal of the source ofpower, and thereby to de-energize the electromagnet at each station; astop signal at each station; means at each station operatingin responseto the de-energization of the corresponding electro-magnet, fordisplaying the corresponding stop signal; a proceed signal at eachstation; a normally-open switch at each station,

closed by the operation of the corresponding con- 7 trol means; means ateach :station, -controlled by the closing of the correspondingnormallyopen switch, for displaying the corresponding proceed signal;and means control-led by the opening of the said normally-closedswitches providing for the display of only one of the said proceedsignals, when more than one of the said normally-open switches areclosed.

19. A railway block signaling system for a plurality of separatedstations, having in combination, a source of power; signaling means ateach of said stations; a control relay at each station; means at eachstation, controlled by the corre sponding control relay, for operating.ie corre sponding signal; a normally-closed switch at each station; afirst line connection extending to each station; a norma11y-energizedoperating-coil for each control relay, each coil'having one terminalconnected to the said first line connection and its other terminalconnected to one terminal of the said source of power; a second lineconnection connecting the said first line connection to the otherterminal of the said source or power, the said second line connectionincluding the normally-closed switch at each station connected in seriestherewith; control means at each station operable to open thecorresponding normally-closed switch, for opening the said second lineconnection, and thereby de-energizing each of the operating coils of thesaid control relays so as to render the control relay at each stationeffective to control the corresponding signaling means.

JOHN A. MILLER.

